Hiroyasu Koga

{{Infobox person

| name = Hiroyasu Koga

| native_name = {{Infobox Japanese

| kanji = 古賀浩靖

}}

| image =

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| caption =

| birth_name =

| birth_date = {{birth date and age|1947|8|15|df=y}}

| birth_place = Takikawa, Hokkaido, Japan

| death_date =

| death_place =

| nationality =

| other_names = {{unbulleted list|Furu-Koga|Hiroyasu Arechi (荒地浩靖)}}

| education = Kanagawa University

| occupation =

| known_for = Role of kaishakunin (介錯人) in the 1970 Mishima Incident

}}

Hiroyasu Koga ({{CJKV|j=古賀浩靖}} Koga Hiroyasu, born 15 August 1947) is a former Tatenokai member and kaishakunin responsible for the decapitations of Yukio Mishima and Masakatsu Morita during their seppuku on November 25, 1970. He studied law at Kanagawa University and intended to become a lawyer.

Koga, known by the nickname Furu-Koga (distinguishing him from another Tatenokai member named Masayoshi Koga who was in turn nicknamed Chibi-Koga, {{lang|ja|小賀}}), was a skilled practitioner of kendo (swordsmanship). It was originally planned that Mishima would be decapitated by Masakatsu Morita, the Tatenokai's student leader; however, Morita was not trained in the sword and failed, at which point Koga stepped in to complete it. Koga then decapitated Morita as part of Morita's own seppuku.{{cite book |last=Stokes |first=Henry Scott |date=2000 |title=The Life and Death of Yukio Mishima |url=https://books.google.com/books?id=PjYSgQSCIlsC&pg=PA30 |location=Lantham, Maryland |publisher=Rowman & Littlefield |pages=30–32 |isbn=978-0815410744 |accessdate=November 10, 2014 }}

Koga and two other participating Tatenokai members (Masayoshi Koga and Masahiro Ogawa) went on trial on March 24, 1971,{{cite news |author= |url=https://news.google.com/newspapers?nid=1300&dat=19710324&id=sNxUAAAAIBAJ&sjid=ppADAAAAIBAJ&pg=5096,4905539 |date=24 March 1971|newspaper=The Age |location= |agency=AAP-Reuter |accessdate=18 December 2014 |title=Warrior code goes on trial}} facing charges of bodily injury, violence, illegal possession of firearms and swords,{{cite news |author= |url=https://news.google.com/newspapers?nid=1891&dat=19701124&id=X6ofAAAAIBAJ&sjid=l9YEAAAAIBAJ&pg=4923,3395431 |date=27 November 1970|newspaper=Gadsden Times |location= |agency=AP |accessdate=18 December 2014 |title=3 Survivors Of 'Pact' Charged}} and assisting a suicide.{{cite news |author=Axelbank, Albert |url=https://news.google.com/newspapers?nid=1798&dat=19710106&id=2xMfAAAAIBAJ&sjid=CI0EAAAAIBAJ&pg=6776,640034 |date=6 January 1971|newspaper=Sarasota Journal |location= |agency=NANA |accessdate=18 December 2014 |title=Japan's Patriot: Suicidal Author in 'Hero' Status}} They were convicted and sentenced to four years' penal servitude, and were released in 1974, a few months early.{{cite news |author= |url=https://news.google.com/newspapers?id=4qIrAAAAIBAJ&sjid=nPwFAAAAIBAJ&pg=4788,1077829&dq=hiroyasu+koga&hl=en |date=7 October 1974 |newspaper=Nashua Telegraph |page=2 |title=Japan has freed for good behavior...}}

As of 2005, it was believed that he was a practising Shinto priest at a shrine on Shikoku.{{cite news|last=Sheridan|first=Michael|url=http://markdevlin.com/the-mishima-incident/the-mishima-incident-sunday-times/|archive-url=https://archive.today/20131212041250/http://markdevlin.com/the-mishima-incident/the-mishima-incident-sunday-times/|url-status=dead|archive-date=12 December 2013|date=27 March 2005|publisher=Sunday Times|title=Briton let author commit hara-kiri}} However, an alternative belief is that he never became a Shinto priest, instead becoming the head of the Hokkaido branch of Seicho-no-Ie and was renamed Hiroyasu Arechi. It is further posited that he now resides in Kumamoto.{{cite news |last= Phillips |first=Brian |url=http://grantland.com/features/sumo-wrestling-tokyo-japan-hakuho-yukio-mishima-novelist-seppuku/|date=5 November 2014|publisher=Grantland|title=The Sea of Crises}}